16 September, 2009

Snake foot - or just dinner fighting back?

Snakes are great!

They seem to regularly provide us with a lot of excellent examples of evolution. A few weeks ago it was the fact that they can lose and re-gain the ability to lay eggs.

Now one has been found in China with a freakin leg!

What we probably see here is an example of a suppressed gene function becoming reactivated.

Now some have legitimately expressed concerns that this is simply a swallowed lizard which has punched it's way through the snake, hence the protruding leg. If this is the case, fair enough. Let's wait and see. But snakes have been found in the past with legs or leg-like protrusions, so if it is an actual snake leg, it isn't an isolated incident.

The main point is that the genes for leg growth are clearly present in the genome. Snakes evolved from limbed ancestors and then lost the gene function, but not the gene, that controls limb growth and development.

(From Pharyngula)

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